Mystery electronic devices under rear seat

[GRNSHRK]

While I was working on some other stuff and had the rear seats out, I've seen these 2 electronic devices before and never gave them much thought, but curiosity got the better of me this time

They are located under the left hand seat

This is a series 1 version, anybody know what the function of these are

I'll take a look in "the big blue book" as well and see if I can find any info

[RossDinan6]

Plug the part numbers into realoem or your favorite search engine. That'll get you something. I tried with the black one. The part number came up as a seat belt alarm: https://www.ebay.com/itm/DH-BMW-OEM-136 ... 4#viTabs_0

I couldn't make out the number on the other module.

[GRNSHRK]

Thanks Ross, now why didn't I think of that

However, thanks to the "Big Blue Book", here's the skinny

The larger silver unit is for the "Lamp Test Unit for Check Control", the test panel that Series 1 versions have

Interesting location

The smaller black unit is the "Belt Time Unit Relay", which I presume to be the relay that turns on the "Fasten Seat Belt" light that comes on for a few seconds, then turns off

Some of these conversions from German to English leave a bit to be desired